The 1984–85 Southern Football League season was the 82nd in the history of the league, an English football competition.
The Premier Division consisted of 20 clubs, including 15 clubs from the previous season and five new clubs:
| Competition: | Southern Football League Premier Division |
| Season: | 1984–85 |
| Winners: | Cheltenham Town |
| Promoted: | Cheltenham Town |
| Relegated: | AP Leamington Gloucester City Trowbridge Town |
| Matches: | 380 |
| Total Goals: | 1144 |
| Prevseason: | 1983–84 |
| Nextseason: | 1985–86 |
The Midland Division consisted of 19 clubs, including 16 clubs from the previous season and three new clubs:
| Competition: | Southern Football League Midland Division |
| Season: | 1984–85 |
| Winners: | Dudley Town |
| Promoted: | Aylesbury United Dudley Town |
| Matches: | 306 |
| Total Goals: | 922 |
| Prevseason: | 1983–84 |
| Nextseason: | 1985–86 |
The Southern Division consisted of 20 clubs, including 17 clubs from the previous season and three new clubs:
Also, at the end of the previous season Hillingdon Borough was renamed Hillingdon.
At the end of the season Hillingdon merged with London Spartan League club Burnham to form a new club Burnham & Hillingdon, who took over a place in the Southern Football League.
| Competition: | Southern Football League Southern Division |
| Season: | 1984–85 |
| Winners: | Basingstoke Town |
| Promoted: | Basingstoke Town Gosport Borough |
| Matches: | 380 |
| Total Goals: | 1085 |
| Prevseason: | 1983–84 |
| Nextseason: | 1985–86 |